Tyrosine Improves Reaction Time in Women

by | May 10, 2017 | 2014, Amino Acids, Cognitive Health, Tyrosine, Women's Health

Written by Greg Arnold, DC, CSCS. Participating healthy females demonstrated that tyrosine supplementation may enhance cognitive control by promoting “response inhibition” but not “response execution”.

natural healthCognitive impairment is a serious health issue that confronts elderly people. Fortunately, research is now identifying ways to slow the progression of cognitive impairment. These include a Mediterranean Diet 1, and daily supplementation with as much as 25 mg per kilogram of bodyweight of magnesium 2, and 1,200 milligrams of omega-3 fatty acids 3.

In a 2014 study 4, 22 healthy females with an average age of 21 were given, after overnight fasting and on an empty stomach, 400 milliliters of orange juice with either 2 grams of tyrosine or 2 grams of a cellulose placebo dissolved in the juice. One hour post-consumption they completed a 30-minute cognitive task on a computer called a “stop-signal task” that has been used in previous research 5,6 and is a measure of reaction time.  The subjects then underwent a “washout” period for 7 days and switched supplement groups.

The researchers found a significant benefit with tyrosine supplementation to stop-signal reaction time. Specifically, reaction time was, on average, 6.2% faster than the placebo group (214 versus 228 milliseconds, p < 0.05). Commenting on these results, the researchers stated that tyrosine is the precursor to dopamine, a crucial brain nerve chemical 7.

“Our results fit with the idea that, in healthy humans, tyrosine works against the phenomenon of  “ego-depletion”—the exhaustion of limited cognitive control resources 8. Demanding tasks, such as stopping on time, may deplete the available control resources more than easy tasks, such as reacting to go signals. Accordingly, tyrosine may be able to replete the missing resources when more control is needed to carry out the task.”

For the researchers, “the supplementation of tyrosine, or tyrosine-containing diets, may promote cognitive enhancement in inexpensive, efficient, and healthy ways.”

Source: Colzato, Lorenza S., et al. “Eating to stop: tyrosine supplementation enhances inhibitory control but not response execution.” Neuropsychologia 62 (2014): 398-402.

© 2014 Elsevier Ltd. All rights reserved.

Greg Arnold is a Chiropractic Physician practicing in Hauppauge, NY.  You can contact Dr. Arnold directly by emailing him at PitchingDoc@msn.com or visiting his web site at www.PitchingDoc.com

References:

  1. Valls-Pedret C, Sala-Vila A, Serra-Mir M, et al. Mediterranean diet and age-related cognitive decline: a randomized clinical trial. JAMA internal medicine. 2015;175(7):1094-1103
  2. Liu G, Weinger JG, Lu Z-L, Xue F, Sadeghpour S. Efficacy and safety of MMFS-01, a synapse density enhancer, for treating cognitive impairment in older adults: a randomized, double-blind, placebo-controlled trial. Journal of Alzheimer’s Disease. 2016;49(4):971-990
  3. Bo Y, Zhang X, Wang Y, et al. The n-3 Polyunsaturated Fatty Acids Supplementation Improved the Cognitive Function in the Chinese Elderly with Mild Cognitive Impairment: A Double-Blind Randomized Controlled Trial. Nutrients. 2017;9(1):54
  4. Colzato LS, Jongkees BJ, Sellaro R, van den Wildenberg WP, Hommel B. Eating to stop: Tyrosine supplementation enhances inhibitory control but not response execution. Neuropsychologia. 2014
  5. Colzato LS, van den Wildenberg WP, Hommel B. The genetic impact (C957T-DRD2) on inhibitory control is magnified by aging. Neuropsychologia. 2013;51(7):1377-1381
  6. Colzato L, Van den Wildenberg W, Van der Does A, Hommel B. Genetic markers of striatal dopamine predict individual differences in dysfunctional, but not functional impulsivity. Neuroscience. 2010;170(3):782-788
  7. Baumeister RF, Bratslavsky E, Muraven M, Tice DM. Ego depletion: Is the active self a limited resource? Journal of personality and social psychology. 1998;74(5):1252.